Not played in over 10 year & am getting an urge to play again. What are the diffrences between Classic & Deluxe, i have played Deluxe but i dont remember what the diffrences were. I still have my original CD but i do not have HDD.

HD Deluxe has many improvements but also some new bugs.
the main improvements are:
- new graphic engine incl. Mip-Mapping, Texture filtering, Anti-Aliasing, Bump maps, higher scaled textures, etc.
- game engine is more stable
- some missions are a bit changed
- addon and editor support

the negative things are:
- humans have no individual faces anymore
- humans don't split when dying in explosions
- AI can't use grenade and knife correctly (they can, but less aggressive than in Classic)